This application incorporates by reference Taiwanese application Serial No. 89117960, Filed on Sep. 1st, 2000.
1. Field of the Invention
The invention relates in general to a document separating mechanism, and more particularly to a document separating mechanism for an automatic document feeder capable of being applied to the fax machine, scanner, or printer.
2. Description of the Related Art
Referring to FIG. 1, a lateral view of a traditional Automatic Document Feeder is shown. The feeding roller 102 carries the fed documents 100 to move forward. The fed documents 100 are sequentially pressed in between the feeding roller 102 and the rubber friction pad 106 with the elasticity of the spring unit 108 below the rubber friction pad 106. The input tray 110 for positioning the fed documents 100 has an inclined plane descending toward the feeding roller and friction pad.
While the fed documents 100 are placed on the input tray 110, the fed documents 100 are slid along the surface of the input tray 110 for positioning by the force of the gravity or the conveyance of the pick roller (not shown in FIGs). Generally speaking, the coefficient of friction for the feeding roller 102 and the fed documents 100 is greater than that between the fed documents 100 themselves and greater than that of the rubber friction pad 106 and the fed documents 100. The xcexc1, is assumed to be the coefficient of friction for the feeding roller 102 and the fed documents 100, the xcexc2 is assumed to be the coefficient of the fed documents 100 themselves, and the xcexc3 is assumed to be the coefficient of the rubber friction pad 106 and the fed documents 100, wherein xcexc1 greater than xcexc2 greater than xcexc3.
As the feeding roller 102 starts to rotate on its axis 104, the first document 100a moves forward by the frictional force between the feeding roller 102 and the first document 100a, since the coefficient of friction for the feeding roller 102 and the fed documents 100 xcexc1 is greater than that of the fed documents 100 themselves xcexc2. The first document 100a departs away from the other fed documents 100b and then comes into contact with the rubber friction pad 106. Since the coefficient of the fed documents 100 xcexc1 is greater than that of the rubber friction pad 106 and the fed documents 100 xcexc3, the first document 100a carried by the feeding roller 102 proceeds to move forward and is consequentially delivered. However, this caused the multiple feeding condition by utilizing the traditional Automatic Document Feeder due to the inadequate arrangement of the documents.
Referring to FIG. 2, a multiple feeding condition of the FIG. 1 arrangement is shown. When the fed documents are not sequentially arranged in order as shown in FIG. 1 and fail to be pressed by the feeding roller 102, the coefficient of friction of the documents 200a and the other fed documents 200b is smaller than that of the fed documents 200b themselves so that the documents 200a depart away together from the other fed documents 200b. Thus, the documents 200a are all pressed in between the feeding roller 102 and the rubber friction pad 106 with the elasticity of the spring unit 108 below the rubber friction pad 106. Thus, the documents 200a move forward and it comes into multiple feeding condition. Other conditions caused by the inadequate arrangement of the documents, such as the position of the backward document is ahead of the forward document or the inadequate thickness of the documentxe2x80x94too thick or too thin, are likely to result in the multiple feeding condition or a jam condition.
It is therefore an object of the invention to provide a document separating mechanism for the Automatic Document Feeder, which can improve the multiple feeding condition caused by the variation of the documents and prevent the multiple feeding or jam condition as result of the inadequate arrangement of documents.
The invention achieves the above-identified objects by providing a document separating mechanism for an Automatic Document Feeder. The document separating mechanism is an elastomer with the features of having a vertical plane and an arc surface, wherein the vertical plane is perpendicular to the main plane and capable of resisting the leading edges of the documents directly or indirectly. The arc surface is a turning plane for joining the vertical plane and the main plane.
The invention achieves the above-identified objects by providing a document separating mechanism for an Automatic Document Feeder. The document separating mechanism is an elastomer with the features of having a vertical plane and an arc surface, wherein the document separating mechanism includes the first document guiding incline and the second document guiding incline which are linked to the main plane with the same slope respectively and capable of making the documents being pressed by the feeding roller and arranged in order initially.
The invention achieves the above-identified objects by further providing an Automatic Document Feeder. The Automatic Document Feeder includes an input tray, a document separating mechanism, a feeding roller, and a rubber friction pad, wherein the feeding roller for carrying the document to move forward. The rubber friction pad along with a spring unit below makes the document being pressed in between the feeding roller and the rubber friction pad with the elasticity of the spring unit. The input tray has an inclined plane descending toward for positioning the fed documents. The document separating mechanism is an elastomer for providing a resistance to restrain the second or the latter document from moving along.